So called, from the identity tag worn by soldiers of the Battalion, the Green Triangle tells the story of one of the Territorial Units of the Notts and Derby Regiment, and its service in the Great War which began with helping in the suppression of the 1916 Easter Rising in Dublin. After a spell training on Salisbury Plain, the Battalion arrived in France and fought at Le Verguier on the Somme and the following year at Bullecourt. During the Ludendorff Spring offensives in 1918 it was involved in the defence of Mt. Kemmel.